#include<string>
#include<vector>
#include<algorithm>

using namespace std;

class Solution {
public:
    bool isUnique(string astr) {
        if (astr.size() == 0 || astr.size() == 1)
        {
            return true;
        }
        vector<int> v;
        for (auto& e : astr)
        {
            v.push_back(e);
        }
        
        sort(v.begin(), v.end());
        int count = v[0];
        for (int i = 1; i < v.size(); i++)
        {
            if ((count ^ v[i]) == 0)
                return false;
            else
            {
                count = v[i];
            }
        }
        return true;
    }
};

int main()
{
    Solution s;
    string str("iluhwpyk");
    s.isUnique(str);
    return 0;
}